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Finding the Fourth Proportional to 686.53, 947.45 and 421.00

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Solution

The fourth proportional to 686.53, 947.45 and 421.00 is: 581.00

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.53 : 947.45 = 421.00 : x
  2. Step 2: Convert to fraction form
    686.53/947.45 = 421.00/x
  3. Step 3: Cross multiply
    686.53x = 947.45 × 421.00
  4. Step 4: Simplify right side
    686.53x = 398,872.77
  5. Step 5: Solve for x
    x = 398,872.77/686.53
  6. Step 6: Final answer
    x = 581.00

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.